Absorbent articles such as sanitary napkins, incontinent devices, diapers, wound dressings and other products are well known. These articles absorb liquid and retain the liquid within a core. The interior or topsheet of the absorbent article is made of a flexible plastic film material. Many attempts have been made to overcome the negative characteristics of the glossy or "plastic" look and sticky tactile feel to the plastic films. It is therefore desirable to produce absorbent devices which have a cloth-like look and feel to a user's skin.
Many types of films have been proposed to overcome these tactile problems, including the use of microapertured polymeric webs. Various types of formed or perforated films and processes for making formed films are disclosed in: U.S. Pat. Nos. 3,871,378; 3,929,135; 4,041,951; 4,259,286; 4,323,069; 4,324,246; 4,327,730; 4,342,314; 4,351,784; 4,463,045; 4,508,256; 4,541,794; 4,552,709; 4,629,643; 4,741,877; 4,772,444; 4,878,825; 5,158,819 and Des. 268,962 which depict a variety of absorbent articles using cell shapes and surface texturing or aperturing techniques aimed at providing a film having the desired aesthetic characteristics.
While these films allow fluid passage therethrough, there is a considerable top surface area which does not allow passage of fluid through the film onto an absorbent core below. Thus, the areas of film between the apertures still adhere to the wearer's skin, especially when there is liquid present. This adherence also results in a sticky or plastic perception against the wearer's skin.
Another attempt to overcome the disadvantages of plastic films involves the use of flocked films, where adhesives are used to bond fibrils and/or fibers to a plastic film. However, the application and handling of the adhesive material onto a formed perforated film has many disadvantages. It is difficult to uniformly apply the adhesive to the formed film layer such that the fibers adequately adhere to the film. The fibers tend to rub off and produce "lint" on the wearer. Further, the adhesive materials, whether aqueous or solvent-based, bring additional chemicals into direct contact with the wearer's skin. These adhesives sometimes result in allergic and/or sensitive reactions, such as diaper rash. In addition, the environmental concerns of handling, application and recovery of the volatile materials in the adhesive materials must be addressed.
Another attempt to overcome the disadvantages of plastic films involved a process wherein thick layers of fibers are laminated to plastic films by pulling the fibrous webs under tension, for example, U.S. Pat. No.4,995,930 and German DE 40-16-348-A1. However, these processes have drawbacks in that only thick layers of fibrous material can withstand the applied tension and maintain their web integrity while being laminated to a plastic film. However, in many end uses it is undesirable to have thick layers of fibers on the plastic film. Thick layers of fibrous webs will retard the flow rate of fluid into the absorptive device. They will also, by their dense mass of fibers, retain fluids within themselves by capillary retention. This will yield a sensation of wetness to the user. Both of these negative attributes of prior art are overcome by the present invention.
Accordingly, it is one object of the present invention to provide a formed film having a thin layer of fibers adhered thereto, which film has an aesthetically desirable cloth-like look and tactile feel.
It is another object of the present invention to provide a cloth-like three-dimensional fibrous coated polymeric material which does not produce perceptible noise typically associated with plastics when worn by a user.
Another object of the present invention is to provide a three-dimensional fibrous coated polymeric material which is suitable for use disposable absorbent product, such as diapers, catamenial pads and adult incontinent products and wound dressings.
Another object of the present invention is to provide a method and apparatus for producing three-dimensional polymeric webs coated with a fibrous material that is so light and thin that it cannot maintain its own integrity under tension.